Abstract
A study was carried out to screen a set of 204 genotypes consisting of germplasm and advance breeding lines for heat tolerance. The study of genetic variability among these genotypes for various morpho-physiological traits revealed high PCV and GCV for number of dried squares, number of fruiting points and leaf area. The results of principal component analysis showed that the first six principal components with eigen values more than unity contributed 81.41% of the variability among genotypes and the traits like canopy temperature, relative water content, specific leaf weight, number of dried squares, plant height, number of fruiting points, leaf area and the phenological traits contributed significantly to total variability. The two genotypes viz., CPD-424 and EC560323 were identified as highly vegetative heat tolerant lines which can be used as donor parents in the heat tolerance breeding programmes.